Express a function - Trigonometic Problem

1. May 3, 2012

okh

Right Trapezium - Simple Problem Using Trigonometry

1. The problem statement, all variables and given/known data
http://img207.imageshack.us/img207/8510/imagejat.jpg [Broken]
ABCD is a right trapezium. CB = 3 = CD. P is a point of CB. The angle CDP is called x.
I have to express the function
f(x) = DP + CP
and I have to find the interval in which the function can be considered.
2. Relevant equations

3. The attempt at a solution
I've found the function:
http://img836.imageshack.us/img836/848/imageuox.jpg [Broken]

But I can't understand how I can find the interval.
Thank you very much for helping!

PS: the solution on my book is 0<=x<=30º.

Last edited by a moderator: May 6, 2017
2. May 3, 2012

SammyS

Staff Emeritus
Re: Right Trapezium - Simple Problem Using Trigonometry

What are the possible values of DP + CP ?

Last edited by a moderator: May 6, 2017
3. May 3, 2012

okh

Uhm.. What do you mean? It depends on which x you choose. The function express that sum, indeed.

4. May 3, 2012

scurty

There is a minimum value for DP + CP and a maximum value for DP + CP. What is the range of values and how does that relate to choices of x in your equation?